System of control.



No. 897,031 PATENTED AUG. 25,1908. E. W. STULL.

SYSTEM OF CONTROL.

APPLICATION FILED JAN.20,1908.

WNW/yaw M w M W 0% w PQRATION OF NEW JERSEY, AND THE A' CORPORATION OFOHIO. I

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w. s'rUnL. or nonwoon, onto, assietvon TO atuscaannnns conranv, A COR"BULLOCK nnno'reic MANUFACTURING COMPANY,

'SYSTEM or contract...

Specification o1 Lettere'Patent.

1?aten.tecl Aug. 25, 1908.,

Application filed Jannary 20, 1908. Serial No. %11,616.

To 'ail whomit' may concern:

' Be it known that I, Ennnrr W. seen, a

' citizen of the United States, residing at Nor 'ments for preventinSerial No. 324,133, filed June which the followingis a full, clear, andexact specification. "My inventionv relates to controllersv for electric.motors and especially to'arrangeg flashing atthe contacts of railwaycontrollers. This present invention-is an improvementon that shownin'my'co-pending application 30, 1906. It frequently happens, especiallywhen a car is being notched along, that dangerous arcing or flashingoccurs at the controller contacts when the controller is moved to offposition. Sometimes this arcing'will burn out the controller andabsolutel dis I able the car.

. It is the object of my invention entirely to avoid flashing at thecontroller contacts and to break the motor circuit elsewhere. Thisattained without requiring any change in o'r addltlon to the controllerproper.

Broadly niy invention comprises the combination with a motor controllerof a switch from the description and drawings and will be particularlypointed out in the claims.

The single figure of the drawing shows diagrammatically one embodimentof my invention.

The controller shown in this figure may be of any desired type, but ishere shown as a series-parallel controller for two electric motors AandB. The controller drum 15 has operative positions 1 to 13 inclusive andis provided with contact segments cooperating with stationary contactfingers 16 to 28 in- As the controller is moved be tween positions 1 andS the resistance R in the motor circuit is varied with the motorsconnected inseries. Between positions 8 and 9 the connections of themotors are changed from series to parallel. Between posit-ions 9 and13the resistanceit IS varied w1th the motors connectedin parallel.

The contact finger 16 is connectedt-o the trolley or other collectingdevice ,3l. The

contact finger 1.7 is connected to the lower end of the resistance Bthrough the magnetically operated switch S and its blowout coil 32 andoperating'solenoid' 36. The solenoid 36, however, is normallyshortcircuited by a a second magnetically operated switch 34, which isbiased toward closed position. The operating solenoid 35 of the switch34 is connected in series between the contact fin 'er 18' and. a pointonthe resistance R. The

solenoid 36 tends to open the switch S whenever it is energizethbut itis only energized when the switch 34 is open. The switch S is biasedtoward closed position, and normally held in such closed position byaspring 33. A dash pot or other time limit device 37 retards the closingmovement of such switch, but allows a free opening movement thereof.

The operation of my invention is as follows: When the controller ismoved into its first operative position the motor circuit is "completedfrom trolley 31 through contact finger 16, the proper contact segmentson the controlling drum, contact finger 17, blowout coil 3'2, switch S,switch 34 short-circuit ing solenoid 36, the whole of resistance R, andthe motors A and B to ground. In this position the solenoid 36 isdeenergized. 'hen the controller is moved into its second operativeposition, the lowest section of resistance it and the switch S with itsappurtenances will be shunted by the engagementof contact finger 18-andits cooperating contact segment on the drum. This completes iicicntlystrongly to operate the switch S.

The further forward movement of the controllcr dcencrgizcs magnet 35 andvaries the motor circu ts 111 any desired manner, butthis latter, havingnothing to do with my present invention, will not be described indetail. VVhen the controller in its backward movement reaches position2, magnet 35 is energized to open the switch 34. Upon finthcr backwardmovement the switch S, solenoid 36, and lowest section of resistance Itare first momentarily connected in shunt to the solenoid But as statedabove, the resistances of these parts are preferably so proportionedthat with this connection the solenoid 36 is no energized sutlicientlystrongly to open the switch S. However, innnediately after the shuntconnection. is made, the contacttinger 18 and the cooperating contactegment on the drum are disengaged, thus throwing the ,whole currentthrough the switch S and solenoid .36, the switch 34 now being open.immediately opens the switch S, the upward extension of its core holdingthe switch 3% open, and thus the motor circuit is broken at the contacts29 and 30. Any arcing that takes place at these contacts isextinguisl'ied by the blow-out magnet 32. Upon further backward movementof the controller to oil position no arcing takes place at thecontroller contacts because the motor circuit is wholl broken. In orderto allow the motorman sullicient time to more the controller from [irslto oil position, the closing movement of the switch S is retarded by thedash pot 37, the opening movement of this switch being unretarded. Theswitch at which the motor circuit-is broken may be located at an desiredplace but is preferably so located as to be out of sight of the passergers.

In some controllers, as in the one shown, the motor circuit is broken asthe controller moves between the last series and. the lirst parallelpositions. As the motors usually have considerable counterelcctroinotiYe force at this time, thus gear-(l3 reducing sparking whichwould otherwise take place at the controller, it is generallyunnecessary to provide for having the circuit broken elsewhere than atthe controller contacts when L However, by a slight this change is made.rearrangeincnt of the parts this can be done if desired.

Many modifications in the particular ar- Tho solenoid. 36

rangernenthere shown and described may be made without departing fromthe spirit and scope of my invention, and all theseobvious-modifications I aim to cover in the ollowing claims.

What I claim as new is A 1.- In combination, a motor controlle z, aswitch, a magnet for opening said switch to break the motor circuit, andconnections whereby said magnet-is energized only when the controller ismoved backward to it's first operative position.

2. In eombinatit'in, a motor controller, a

normally closed switch, a magnet for opening said switch, and means forenergizing said magnet only when the controller in its backward movementreaches a predetermined position.

3. In combination, a controller for electric motors, a normally closedswitch. through which the motor current is supplied when the controlleris in a predetermined position, a magnet for opening said switch, andmeans for energizing said magnet only when the controller in itsbackward movement passes through such predetermined position.

et. In combination, a controller for electric motors, a normally closedswitch thrmigh which the motor currentis supplied when the controller isin a certain position, anormally shortwircuited magnet which whenenergized tends to open said switch, and means for opening theshort-circuit around said magnet when the switch in its backwardmovement reaches ,a predetermined position. 5. In combination, a motorcontroller, a switch biased to closed position and in series with saidcontroller when the latter is in a certain position, a magnet which whenenergized tends to open said switch, a second switch short-circuitiirgsaid magnet, a second magnet tending to open said second switch, andmeans for connecting said magnets in circuit in different positions ofthe controller. In testimony whereof I afli); my signature, in thepresence of two witnesses.

EMMETT "W. STULL.

IYitnesses:

Gno. B. SOHLEY, Fnnn J. Kl'Nsl-IY.

